Reduced friction catheter introducer and method of manufacturing and using the same

ABSTRACT

Tear-away sheath introducers for catheters, methods for making such introducers, and methods for using such introducers are described. The sheath introducers contain movable valves that are encapsulated in a movable housing that allows the valve to move along the axis of the introducer. As the movable valve and housing travel along the axis, a portion of the hub protrudes past the valve and is exposed. As well, the sheath introducers can also contain a stationary valve and housing that can be opened to expose a portion of the hub when a conduit penetrates the stationary valve. The conduit can include a one-way valve actuator that can penetrate and open the valve, yet remain attached to a portion of the introducer when the introducer is split for removal from a patient. In both instances, the protruding portion of the hub contains a friction-free pathway for a catheter into the sheath introducer.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 11/531,339, filed Sep. 13, 2006, which is acontinuation-in-part of U.S. patent application Ser. No. 11/288,959,filed Nov. 29, 2005, which claims the benefit of priority to U.S.Provisional Patent Application No. 60/631,397, filed Nov. 29, 2004, eachof which applications is incorporated herein by reference in itsentirety.

FIELD OF THE INVENTION

The invention relates to medical devices and methods for manufacturingsuch medical devices. In particular, the invention relates tointroducers for catheters, methods for making such introducers, andmethods for using such introducers. More particularly, the inventionrelates to self-sealing sheath introducers (both tear-away andnon-tear-away), methods for manufacturing such introducers, and methodsof using such introducers in medical procedures.

BACKGROUND OF THE INVENTION

Tear-away sheath introducers (“sheath introducers” or “introducers”) andtheir use as medical devices are well known in the art. See, for exampleU.S. Pat. Nos. 6,814,718, 6,808,520, 6,808,509, 6,796,991, 6,740,101,6,712,791, 6,712,789, 6,695,810, 6,641,564, 6,632,234, 6,623,460,6,599,302, 6,361,559, and 5,558,652, as well as U.S. Patent ApplicationsNos. 20040260243, 20040254534, 20040176781, 2004006330, 2004097863, and2002072789, the disclosures of which are incorporated herein byreference. These introducers are used in medical procedures to insert acatheter into the body and provide vascular access to the vessel of apatient. The catheters are inserted via the introducers by first using aneedle to create an access site. A dilator is then used to dilate theaccess site to allow a larger-diameter sheath introducer to beintroduced into the vessel through the access site. The catheter is theninserted through the sheath introducer and into the vessel. After thecatheter has been inserted, the sheath introducer is removed, leavingthe catheter in the vessel.

As shown in FIG. 19, conventional tear-away (or split) sheathintroducers 100 usually contain four major components: (1) a dilator140; (2) a tear-away sheath hub 110; (3) a tear-away valve 120; and (4)a tear-away sheath 130. The dilator 140 facilitates insertion of thesheath introducer 100 into the vascular system and maintains the insidediameter of the sheath 130 during insertion. The dilator 140 is normallylocked into the hub 110 in order to keep it seated within the sheath130. The dilator 140 typically contains a tapered tip 142 to facilitateinsertion into the vascular system with the other end 144 of the dilatorcontaining a standard medical luer hub 146. Both the distal end 142 andthe proximal end 144 of the dilator 140 are usually manufactured of arigid polymer.

The tear-away hub 110 provides a means to contain the valve 120 whileconnecting the valve 120 and the sheath 130. The hub 110 typically has a“T” shape with the opposing ends of the “T” being grasped and pulled tosplit both the valve 120 and sheath 130. Thus, the hub 110 provides amechanism to split the sheath 130 into two portions and allow theintroducer to be split and removed from around the catheter. The hub 110is also often manufactured of a rigid polymer.

The tear-away valve 120, however, is typically made of a flexiblematerial (such as silicone) that provides a self-sealing slit. The valve120 may be designed as one piece that tears in half during the splittingprocedure, or as two (or more) pieces that separate from each otherduring the splitting procedure. With conventional introducers, the valve120 is encapsulated by the hub 110.

The tear-away sheath 130 is normally manufactured as a thin-walledstructure, often as an extrusion. The extrusion contains splittingmeans, i.e., score lines that facilitate splitting or a self-splittingpropagating material (such as linearly-directional extrusion). Theproximal end 132 of the sheath 130 is attached to the hub 110 usingover-molding or any other known attachment mechanism. The distal end 134of the sheath 130 can be tapered to provide a smooth transition at thedilator/sheath interface.

To use the introducer 100, it is inserted in the desired vessel. Thenthe dilator 140 is unlocked from the hub 110 and removed to allow roomfor a catheter (or any similar medical device) to be inserted into thesheath. The valve 120 remains stationary inside the hub 110 and blocksair and/or fluid from flowing through the sheath 130 and hub 110 whenthey are left behind after the dilator is removed. The valve 120 keepsthe passage 105 clear until a catheter is inserted into the passage 105through the valve.

The introducer 100 is typically used for larger catheters, i.e., thosewith a diameter of 12 to 16 French. These larger-diameter introducersare rigid due to their diameter and the material used to construct them.This rigidity allows the large catheters to overcome the frictionalforces needed to push the catheter through the valve.

But inserting smaller catheters into smaller introducers is moredifficult. Typical introducers designed for smaller catheters (i.e.,those 3 to 12 French in diameter) are made with open communicationbetween the access site and the vascular system once the dilator isremoved. This open configuration exists because smaller catheters, dueto their smaller diameter and material, are not rigid enough to overcomethe frictional forces needed to push the catheter through the valve. Inother words, it is like trying to “push” a rope through a hole: the rope(i.e., catheter) does not remain rigid enough for a user to push itthrough the hole (i.e., valve).

The open configuration between the vascular system and the environment,however, allows two serious clinical problems. First, air embolism intothe vascular system which can result in patient injury and/or death. Andsecond, release of potentially infectious bodily fluids (includingblood) into the environment, resulting in exposure to the health careprovider.

SUMMARY OF THE INVENTION

The invention relates to tear-away and non-tear-away sheath introducersfor catheters, methods for making such introducers, and methods forusing such introducers. The sheath introducers contain movable valvesthat are encapsulated in a movable housing that allows the valve to movealong the axis of the introducer. As the movable valve and housingtravel along the axis, a portion of the hub protrudes past the valve andis exposed. As well, the sheath introducers can also contain astationary valve and housing that can be opened to expose a portion ofthe hub when a conduit penetrates the stationary valve. The conduit caninclude a one-way valve actuator that can penetrate and open the valve,yet remain attached to a portion of the introducer when the introduceris split for removal from a patient. In both instances, the protrudingportion of the hub contains a friction-free pathway for a catheter intothe sheath introducer. The introducers can therefore be used with anycatheter, regardless of the size or material, because of the reduced oreliminated frictional force between the catheter and introducer.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description of the invention can be understood in light ofFIGS. 1-23, in which:

FIG. 1 is a side perspective view(s) of the introducer assembly in oneaspect of the invention;

FIG. 2 is a side perspective view of a two-piece flexible valve in oneaspect of the invention;

FIG. 3 is a side perspective view of a dilator in one aspect of theinvention;

FIGS. 4 and 5 are section views of a valve housing in one aspect of theinvention;

FIGS. 6 and 7 depict the introducer assembly in another aspect of theinvention;

FIG. 8 is a side view(s) of the sheath introducer in another aspect ofthe invention;

FIG. 9 is a side perspective view(s) of the sheath introducer in evenanother aspect of the invention;

FIG. 10 is a side perspective view(s) of the sheath introducer in yetanother aspect of the invention;

FIGS. 11-12 show a single-piece valve in another aspect of theinvention;

FIGS. 13-14 depict view(s) of the single-piece valve and sheath hub inanother aspect of the invention;

FIGS. 15-17 depict view(s) of methods of increasing the attachmentbetween the sheath and the sheath hub in another aspect of theinvention;

FIG. 18 shows the operation or the sheath introducer in one aspect ofthe invention;

FIG. 19 illustrates a conventional sheath introducer;

FIGS. 20-21 depict view(s) of methods of increasing the attachmentbetween the sheath and the sheath hub in another aspect of theinvention;

FIGS. 22-23 illustrate an introducer containing a stationary valve thatis opened by a movable conduit;

FIGS. 24A and 24B depict perspective views of a sheath introducerincluding a stationary valve and valve actuator according to oneembodiment;

FIG. 25 is a cross sectional side view of the sheath introducer of FIGS.24A and 24B;

FIGS. 26A-26C are various views of the valve actuator of the sheathintroducer of FIGS. 24A and 24B, according to one embodiment;

FIG. 27 is a perspective view of a top cap portion of a hub of thesheath introducer of FIGS. 24A and 24B; and

FIGS. 28A and 28B are cross sectional side views of the sheathintroducer of FIGS. 24A and 24B, showing actuation of the valveactuator.

FIGS. 1-28B presented in conjunction with this description are views ofonly particular-rather than complete-portions of the devices andassociated methods of making and using these devices. Together with thefollowing description, the Figures demonstrate and explain theprinciples of the devices and associated methods. In the Figures, thethickness of layers and regions are exaggerated for clarity. The samereference numerals in different drawings represent the same element, andthus their descriptions will be omitted.

DETAILED DESCRIPTION OF THE INVENTION

The following description provides specific details in order to providea thorough understanding of the invention. The skilled artisan, however,would understand that the invention could be practiced without employingthese specific details. Indeed, the invention can be practiced bymodifying the illustrated method and resulting device and can be used inconjunction with apparatus and techniques conventionally used in theindustry. For example, the invention is described as a micro-introducerfor small catheters (3F-10F in size), but could easily be adapted forany size of catheter or device regardless of the size or intended use.Further, while the invention is described for use with catheters forvascular access, it could be used with any similar device that is usedto grant a physician (or other user) access to a part of the body,whether human or animal.

The invention includes a tear-away or non-tear-away sheath introducerthat contains a movable valve and housing that when moved, allows aportion of the hub to protrude through a valve and be exposed. Theprotruding portion of the hub contains a friction-free pathway for thecatheter. Any inducer having these properties can be used in theinvention, including the sheath introducer described below andillustrated in the Figures.

The sheath introducer of the invention contains several primarycomponents. First, dilator means used to dilate the vascular system andcreate a pathway for the catheter. Second, means for sheathing thedilator means to protect it from the vascular system. And third, valvemeans for keeping the pathway created by the dilator closed until thecatheter needs to be inserted.

One example of the sheath introducer is illustrated in FIG. 1 where theintroducer 10 contains dilation means comprised of a dilator hub 1 and adilator shaft 2. The dilation means is configured to fit within thesheath means comprised of a sheath hub 7 and a sheath 8. The introducer10 also contains valve means comprised of a valve with left and righthalves (4 and 5) contained within valve housing having right and lefthalves (3 and 6) that is attached to the sheath hub 7.

FIGS. 2-5 illustrate detailed views of each of these components. FIG. 2depicts one half of the valve 4, FIG. 3 illustrates the dilator 1, andFIGS. 4-5 show the different views of the valve housing 3. In FIG. 2,the valve contains retention means for retaining the valve to the valvehousing. Any retention means known in the art can be used, includingretention member 12 which seats into a corresponding structure in thevalve housing such as the valve retention slot 15. The valve has a sizeand shape substantially the same as the inner part of the valve housingto which it is retained. Accordingly, the valve half 4 depicted in FIG.2 is substantially circular and with a size that fits within thecorresponding inner surface of the valve housing 3 shown in FIGS. 4-5.The valve can be manufactured from any suitable medical material,including flexible materials like silicone or polyurethane.

FIG. 3 depicts one example of a dilator of the introducer 10. Thedilator 31 can contain any standard medical luer hub, including a hub 1with a gripping mechanism (such as finger grips 11) and lockingmechanism (such as locking ears 9) as shown in FIG. 3. The lockingmechanism locks the dilator 31 into the valve housing by using, forexample, the locking channel 16 contained in the valve housing 3 and 6.The dilator 31 also contains a shaft 2 with a tapered section fordilating the vessel into which it is inserted. The dilator 31 can alsobe manufactured from any suitable medical material, but should be madefairly rigid, yet flexible enough that it can be maneuvered into thedesired vessel by a user.

FIGS. 4 and 5 depict one example of the internal geometry of the valvehousing 3. The valve housing 3 contains any means for securing the valvehousing to the sheath hub 7. In FIGS. 4 and 5, the securing meanscomprises snap features 13, which secure the valve housing 3 to thesheath hub 7 using the mating snap feature 21 (shown in FIG. 6). Usingthe securing means keeps the valve housing (and therefore the valve) ina closed position until it is needed to be opened (i.e., such as whenthe catheter is inserted).

The valve housing 3 also contains any known means for positioning itwith the sheath hub. An example of this positioning means is depicted inFIGS. 4 and 5, where a guide slot 15 and stop post 20 mate with theguidepost 22 of the sheath hub 7 (shown in FIG. 6). The exterior of thevalve housing contains grips 14 that can be employed by the user in thesplitting procedure. The valve housing 3 is constructed of any suitablemedical material that provides the desired rigidity, such as rigidpolymeric materials.

The valve housing 3 can also contain any known interlock mechanismbetween the two halves of the valve housing. An example of thisinterlock mechanism is lock 19 that, when the halves are assembledtogether, serves to maintain uniform travel between both halves of thevalve housing. This interlock mechanism can be supplemented with anyknown mechanism, including the detachable interlock features 17 and 18.

FIGS. 6 and 7 illustrate the various components of the introducer whenassembled together. In FIGS. 6 and 7, the sheath hub 7 and the sheath 8are attached together into an assembly by any attachment means. Examplesof suitable attachment means include insert molding or any mechanicalattachment, such as a friction fit, locking snap fit, solvent or UVbond.

The sheath hub 7 contains several features for its operation. One suchfeature includes valve snap fit grooves and edges 21. These twocomponents, along with the snap feature 13, work together to snap thevalve housing 3 (and 6) to the sheath hub 7. Of course, any similarmechanism can be used to snap these two components to each other. Thesheath hub 7 also contains the guide slot 22, as mentioned above, thatguides the valve housing 3 (and 6) and the hub to the correct locationrelative to each other.

The sheath hub 7 also contains a valve penetration means. The valvepenetration means operates to penetrate the two halves of the valve 4and 5, thereby providing an opening in the valve. Any penetration meansknown in the art can be used for this function. As depicted in FIGS. 6and 7, the penetration means comprise member 23 that is configured tofit between the two halves of the valve 4 and 5. The penetration member23 opens the two halves of the valve when it is forced between them byany action which pushes the member 23 through the valve.

The valve penetration means need not physically force (i.e., push) thevalve halves 4 and 5 apart to penetrate the valve. In this aspect of theinvention, the member 23 penetrates the valve halves 4 and 5 when thevalve housings are pulled apart to expose the member 23. The valvehousings can be pulled apart by the mechanisms described below.

When the penetration member 23 opens the valve in either of thesemanners, port 24 is exposed. The port 24 is the location where thecatheter (or similar device) is inserted. Unlike the conventionalintroducers where the catheter is forced between the valve (whichcreates a friction force that must be overcome by a user), the cathetercan be inserted in the port 24 of the introducers. The port 24 can beconfigured to have less friction than that required in conventionaldevices by providing an inside diameter slightly larger than that of thecatheter insertion member. Alternatively, the port can be configured tohave substantially no friction (“friction-free”) by providing an insidediameter significantly larger than that of the catheter insertionmember. As well, the port 24 can be configured to have less orsubstantially no friction by providing a coating on the inside of theport 24 and/or the outside of the catheter.

The sheath hub 7 also contains activation means. The activation means isused to force the penetration member 23 up through the valve halves 4and 5, move the valve halves (and housing) down over the member 23, orto pull the valve halves apart, to thereby open them and expose member23 containing port 24. Any mechanism that operates in this manner can beuse as the activation means. In the sheath hub depicted in FIG. 8, theactivation means pulls the valve halves apart and comprises a reactionforce member 25 that is formed on the bottom edge of the sheath hub 7.When pressure is applied to the reaction force member 25 by the user, itdepresses the valve housings 3 and 6 and forces the valve halves 4 and 5apart. Of course, any other known mechanism could be used to push orpull the valve apart.

FIG. 8 depicts the introducer in a position ready to accept a catheter.In FIG. 8, the penetration member 23 protrudes out of the valve halves 4and 5. The penetration member 23 need only protrude enough so that port24 is exposed enough for a catheter to be inserted. Typically, the port24 protrudes from about 0.025 to about 0.05 inches above the valve. Inone aspect of the invention, the port 24 protrudes about 0.05 inchesabove the valve.

FIG. 9 depicts one part of a method for using the introducer 10. Afterthe introducer 10 has been inserted into the desired vessel, thecatheter (not shown) is inserted through the introducer. Then, the userpresses on the grips 14 to cause the valve housing 3 and 6 to separatefrom each other. As the pressing continues, the valve halves 4 and 5 andthe sheath hub 7 then separate from each other. Once this initialseparation has occurred, the user can continue pull on the ends of theseparated portions to continue separating the introducer.

FIG. 10 illustrates another part of a method for using the introducer10. In step 1, the introducer 10 has been inserted in the desired partof the vascular system, i.e., the desired vessel. Next, as shown in step2, the dilator is then removed from the introducer. As shown in step 3,removing the dilator still leaves the valve in a closed position. Next,using the actuating mechanism a user makes the penetration memberpenetrate the valve in any of the methods described above so that valveis opened with the port 24 exposed. Then, the catheter (not shown) isinserted into the introducer as shown in step 4. Finally, the introduceris removed by the splitting procedure as shown in step 5.

In some embodiments, the introducer can be configured so that the valveis stationary. In these embodiments, the stationary valve can be openedto expose a portion of a hub when conduit means penetrate the stationaryvalve. With a portion of the hub exposed, the catheter can then beinserted as described above.

One example of these embodiments is illustrated in FIGS. 22-23. FIG. 22depicts an assembled introducer 105 without a dilator. The assembledintroducer 105 contains a sheath hub bottom 107 containing a sheath hubtop 108, and valve means comprised of a stationary valve 104 containedwithin a valve housing 106. The assembled introducer 105 also containsconduit means (i.e., conduit 110) that can move along the axis of theassembled introducer 105.

The valve 104 can be configured to be stationary within the assembledintroducer 105 using any known mechanism. In the embodiments illustratedin FIGS. 22-23, the valve 104 is configured to be stationary by matchingthe extensions 112 of the valve with corresponding indentations 114within a press fit generated between the sheath hub top 118 and valvehousing 106. In other instances, though, the extensions 112 could beconfigured to match indentations made in the valve housing 106 (notshown). In yet other instances, the valve can be configured to bestationary by means of any known adhesive.

The valve housing 106 houses the stationary valve 104 and therefore thebottom of the housing 106 can be configured to substantially match theshape of the valve 104. As well, since the valve housing 106 is locatedon the sheath hub top 118, the bottom of the valve housing 106 can beconfigured to substantially match the upper surface of the sheath hubtop 118. As depicted in FIG. 22, these matching surfaces can besubstantially flat. But any other matching shapes for these surfaces canbe used, including ridged, notched, or an interlocking snap fit.

The valve housing 106 also surrounds the conduit means (i.e., conduit110). Accordingly, the inner surface of the valve housing can beconfigured to substantially match the outer surface of the conduit 110.As depicted in FIG. 22, these two matching surfaces can be configured assubstantially circular in shape. But other geometries for these surfacescan be used, including substantially rectangular, substantially oval,substantially polygonal, or a male/female keyway.

The conduit 110 moves along the axis of the assembled introducer 105from a first position shown in FIG. 22 to a second position shown inFIG. 23. In the first position, the bottom 115 of the conduit remainsabove the closed valve. In the second position, the bottom 115 of theconduit has pierced the valve and forced the valve into an openposition. With the valve in this open position, a catheter can beinserted though the conduit 110 and into the sheath 108.

In other embodiments, the conduit 110 can move into an intermediateposition anywhere between the first and second positions. Theintermediate position can be selected so that the valve is opened by anydesired amount. For example, the intermediate position for the conduit110 can be selected so that a partially opened valve would allow only asmall amount of blood to be exposed, ensuring that the introducer waslocated correctly in a vein.

The conduit means can have any configuration allowing it to operate inthis manner. Thus, the outer surface of the conduit can be configured tobe slightly smaller than the inner surface of the valve housing,allowing the conduit to move easily relative to the valve housing. Ifdesired, additional mechanisms like depth control detents, springs, orcoatings can be used to increase—or, if necessary, decrease—the abilityof the outer surface of the conduit to move relative to the innersurface of the valve housing.

In some instances, the outer surface of the conduit 110 and the innersurface of the valve housing 106 can be configured so that the conduitcan be retained in the first and second positions. Any retaining meansknown in the art can be used, such as markings, depth control detents,springs, threads or the retaining means illustrated in FIGS. 22-23. Inthese Figures, the retaining means comprises at least one notch 121 onthe outer surface of the conduit 110 that substantially matchesindentations 123 and 125 on the inner surface of the valve housing 106.The two (or more) sets of indentations are located where the notch 121will insert when the conduit 110 is in the first and second positions.

The bottom 115 of the conduit 110 can be configured so that it piercesand opens the stationary valve 104. Thus, the bottom 115 of the conduitcan be configured with any shape that will operate in this manner. Insome instances, the bottom 115 is typically given a substantiallypointed or substantially tapered shape. The bottom of the conduit cantherefore initially open the valve and as the conduit moves furtherdown, the opening in the valve becomes wider and wider allowing for asubstantially friction-free passage way through the valve. In someinstances, the bottom of the conduit can be rounded to prevent damage tothe valve.

The top 127 of the conduit 110 can be configured with any shape so thatit guides the placement of the catheter. One example of such a shape isdepicted in FIGS. 22 and 23 where the top of the conduit comprises asubstantial conical shape. The conical shape guides the placement of thecatheter through the top of the conduit and into the inner chamber 120of the conduit 110. The conical shape can, in certain instances, besmooth and rounded so that it is easier to be pushed by a user to openthe valve.

Once the assembled introducer 105 is located in the desired location,the user can open the valve easily by pressing on the top of the conduitmeans. This action forces the conduit 110 from the first position intothe second position, and opens the valve. The user can then place thetip of a catheter in the top of the conduit. As the user pushes on thecatheter, the tip is guided from the top of the conduit 110, though theinner chamber 120, past the opened valve, out the bottom of the conduit,and then into the sheath 108.

Reference is now made to FIGS. 24A-28B, which describe various aspectsof a sheath introducer including a stationary valve that can be openedvia penetration of conduit, according to one example embodiment. As itshares various aspects in common with the sheath introducers describedin previous embodiments, only selected details regarding the presentsheath introducer are described below.

As shown in FIGS. 24A, 24B, and 25, the introducer 205 includes astationary slit valve 204 housed in a sheath hub 207, which in turn isdisposed at the proximal end of the sheath 108. The sheath hub 207includes a top cap 206 that is placed atop the valve 204. Though a slitvalve is depicted here, other types of valves may also be employed inthe introducer. As before, the valve 204 includes extensions 212 on abottom surface thereof that are received into corresponding indentations214 defined in the sheath hub 207 to enable the valve to seat therein.

A valve actuator 210 is also shown in FIGS. 24A, 24B, and serves as oneexample of a conduit to open an introducer valve, such as the valve 204.As shown in FIG. 25, the actuator 210 is received in a cavity 240defined by the hub top cap 206 and is movable by a user to selectivelyopen the valve 204 in preparation for insertion through the introducerof a catheter or other device, as will be described. Note that, thoughconfigured as separate pieces, the hub 207 and top cap 206 can beintegrally formed. Note further that the valve actuator 210 in thepresent embodiment is substantially coaxial with the longitudinal axisof the introducer 205, though in other embodiments the actuator can beoff-center with respect to the longitudinal axis.

Reference is now made to FIGS. 26A-26C, which depict further detailsregarding the actuator 210 as an example of a conduit according to thepresent embodiment. As shown, the actuator 210 includes a bottom 215, atop 227, and a conduit pathway 220 defined therebetween. The top 227includes a ridge and is defined so as to enable a user of the introducerto press the actuator 210 with a downward force in order to selectivelyopen the valve 204 with the actuator bottom 215. An extended surface215A is included at the actuator bottom 215 and is shaped so as topenetrate the slit valve 204 when the actuator is pushed downward, thusopening the valve and enabling a catheter to pass through both theconduit pathway 220 of the actuator and the valve with minimalresistance. In the present embodiment the extended surface 215A isshaped as a partial cylinder to define a C-shaped cross sectional shape,but it is appreciated that other shapes and configurations are possiblefor the extended shapes in other embodiments. For instance, in oneembodiment the extended surface could define a U-shaped cross sectionalshape.

As mentioned, the conduit pathway 220 extends through the actuator 210to enable a catheter to pass therethrough after the actuator has openedthe valve 204. In the present embodiment, the surface of the conduitpathway 220 is conically shaped so as to guide the catheter in itspassage through the actuator. As best seen in FIG. 26A, the actuator 210includes a longitudinally extending channel defined through the side ofthe actuator body. The channel 230 enables the catheter to pass throughand be released from the actuator after placement in the patientvasculature during peel-away of the introducer sheath from the vesselinsertion site. Note that, though it is non-splittable in the presentembodiment, the actuator in another embodiment can be formed assplittable.

FIGS. 26A-26C further depict a plurality of interference featuresdefined on the side of the body of the actuator 210. In the presentembodiment the interference features include a plurality of teeth 232circumferentially defined in a longitudinally stacked arrangement abouta portion of the actuator body. The teeth 232 circumferentially extendfrom either side of the channel 230 to a raised tongue 234 also definedon the side of the actuator 210 opposite the channel. Of course, otherinterference features in addition to what is described herein, includingfeatures disposed at other locations on the actuator, are contemplated.

The teeth 232 of the actuator 210 are configured to engage withcorresponding interference features defined in the cavity 240 of the topcap 206, namely, teeth 242 defined on the inside surface of the cavity.FIG. 27 shows the top cap 206 in an exploded state along its split line,and further depicts the various locations for the teeth 242 according tothe present embodiment. The locations of the teeth 242 are configured toenable the top cap teeth to engage with the teeth 232 of the actuator210 when the actuator is pressed downward into the top cap cavity 240 inorder to open the valve 204. The teeth 242 of the top cap cavity 240 areconfigured to engage the actuator teeth 232 in such a way as to enablefurther downward (one-way) movement of the actuator, but to preventupward actuator movement. In other embodiments, however, it isappreciated that the actuator can be configured to be resettable orreversible, via a spring and two-way interference features for instance,so as to enable the actuator to be pressed downward to open the valve,yet be upwardly retractable so as to close the valve again, if desired.

Grooves 244 are defined on the inside surface of the top cap cavity 240to engage with the tongue 234 defined on the side of the actuator 210when the actuator is received in the top cap cavity. Engagement of theactuator tongue 234 with one of the top cap cavity grooves 244 enablesthe actuator to slide longitudinally within the cavity 240, whilecausing the actuator to retain physical engagement with the respectivehalf of the top cap 206 when the top cap, together with the rest of theintroducer 205, is split apart in order to remove it from the vesselinsertion site. In brief, the side surfaces of the teeth 242 adjacentthe groove of the top cap cavity 240 are angled such that the actuatortongue 234 is captured in and retained by the groove, even when the topcap is split. This prevents the actuator 210 from falling out of theintroducer 205 when split. Thus, the tongue 234 and/or grooves 244operate as retaining members and therefore serve as one example of meansfor preventing separation of the valve actuator from a portion of thehub when hub is split. Note, however, that other means for providingthis functionality may be included in the introducer. For instance, thevalve actuator can be attached to a portion of the sheath hub by aliving hinge, a tether, a magnetic feature, etc. These and other meansfor preventing such separation are therefore contemplated.

The top cap 206 includes tabs 246 that are configured to be received bycorresponding grooves 248 (FIG. 25) defined in the sheath hub 207 inorder to mate the top cap with the sheath hub and secure the valve 204in a sandwiched configuration therebetween. The engagement between thetop cap 206 and the sheath hub 207 can be secured mechanically (e.g.,snap-fit), adhesively, or by other bonding methods (e.g., ultrasonicbonding). In the present embodiment, the composition of the actuator 210includes polypropylene, but in other embodiments an acrylic, e.g.,polymethyl methacrylate, or other thermoplastic or thermoset may beemployed for forming the actuator. In one embodiment, the actuator 210is colored to indicate the French size of the introducer 205. Theprinciples of the present embodiment may be extended to introducers of avariety of French sizes, as was described in connection with previousembodiments.

Reference is made to FIGS. 28A and 28B in describing the opening of thevalve 204 by the actuator 210 of the introducer 205. As shown in FIG.28A, with the actuator 210 in an upward first position, the extendedsurface 215A of the actuator is above and is not in contact with thevalve 204. This configuration is useful for reducing the risk of airembolism and/or blood leakage via the introducer 205 while theintroducer is partially inserted into a vessel of the patient. When theactuator 210 is pressed downward by the user, as shown in FIG. 28B, theactuator is moved from the first position to the second position whereit is brought into contact with the valve 204 such that the extendedsurface 215A penetrates the slit of the valve, thus opening the valve.Note that the movement of the valve actuator 210 from the first positionto the second position is performed in one embodiment via direct fingerpressure on the valve actuator in a direction that is substantiallycoaxial with a longitudinal axis of the valve actuator. This results ina balanced force imparted on the introducer during valve opening.

This provides a clear path via the actuator conduit pathway 220 for thecatheter to pass through actuator, sheath hub 207, and sheath 108 forplacement in the patient's vasculature. Later, when the catheter isplaced, the introducer 205 can be split and removed from the vesselinsertion site. Upon splitting, the tongue and groove engagement of theactuator 210 with the top cap cavity 240 enables the actuator to beretained with a corresponding split portion of the top cap 206. Duringthe introducer splitting and removal, the already-placed catheter willpass through the actuator channel 230 to free the catheter from theactuator, as the actuator is non-splittable in the present embodiment.

In one embodiment, the composition of the sheath hub 207 includes aclear material, such as acrylic, e.g., polymethyl methacrylate, so as toenable the sheath hub to be translucent. This in turn enables a lowerportion 240A of the cavity 240 (FIG. 28B) defined in the sheath hub 207to be visible by the user. So configured, the cavity lower portion 240Acan be observed, such as to determine when venous access has beenestablished as evidenced by the sight of blood in the cavity lowerportion. In one embodiment, one or more magnifiers 250 can be formed inthe sheath hub 207, as seen in FIGS. 24A and 24B, to assist inobservation of the cavity lower portion 240A. The magnifiers can bedefined by any acceptable process, including overmolding,post-manufacture machining, etc. Also, the surface of the sheath hub 207can be polished to increase visibility therethrough.

The introducers described above can be modified and enhanced withseveral optional features. One of these modifications is a modifiedvalve 30 as depicted in FIGS. 11 and 12 that comprises a base 32,extensions 34, and channel portion 36. The base 32 of the valve 30 isconfigured with a size and shape substantially similar to the valvehousing in which the valve 30 rests. The valve 30 can optionally containan indentation 35 of any shape and size that will help the valve split.

The extensions 34 are designed to extend upwards from the valve 30towards the dilator of the introducer. Like the base 32, the extensions34 will abut the valve housing, but the sides rather than the bottom.Accordingly, the size and shape of the extensions 34 are selected tosubstantially match the inner surface of the valve housing which willenclose the valve 30. The extensions 34 contain a notch(es) 38 thatcorrespond to the notches 50 provided in the protruding member 41 (asdescribed below).

The channel portion 36 of the valve 30 also extends in an upwarddirection toward the dilator of the introducer. As shown in FIG. 12, theinner surface 37 of the channel portion 36 will abut the outer surfaceof the outside of the protruding member 41 and is accordingly given asize and shape substantially matching the protruding member 41. Thelength of the channel portion 36 is also selected to substantially matchthe protruding member 41 so that port 44 can be exposed when desired.

The upper surface 42 of the channel portion contains a slit 40. The slit40 does not extend the entire way across the channel portion 36 and sois a non-tear away slit. The slit 40 is held in a closed or sealedposition (position A in FIG. 13) by the valve housing and sheath hub.The slit 40 moves into an open position B when the protruding member 41moves upward through the channel portion 36 and then up through the slit40 (or the valve 30 moves downward over the member 41) as depicted inFIG. 13. Of course, as described above, the valve 30 can be pulled apartto expose the protruding member 41 rather than forced apart.

The channel portion 36 of the valve 30 can also operate as a sealingmeans around the protruding member 41. The sealing means helps provide aseal between the vascular system and the environment when the protrudingmember 41 has forced the slit 40 open. This sealing function isillustrated in FIG. 13 where the protruding member 41 is shown in itsextended state, i.e., protruding above the valve 30. The channel portion36 fits snugly around protruding member 41 so that it provides a seal.Optionally, a coating can be added to the inside of the channel portion36 and/or the outside of the protruding member 41 to increase thissealing function. As shown in FIG. 12, the channel portion 36 canoptionally contain a ring sealing member(s) 39 to increase the sealingfunction.

The advantage of valve 30 is that it can also serve as a flash-backchamber. If the valve 30 (and associated parts of the hub sheath) ismade from a translucent or transparent material, it allows the user toview the inside of the valve 30. If sheath introducer 10 is placed inthe proper location (i.e., in the venous system), blood will enter thevalve chamber resulting in a red color as an indication that the sheathintroducer is placed correctly. Using a translucent or transparentmaterial for the valve 30 therefore allows the user to look through thevalve and determine whether this red color is showing.

As mentioned above, a seal can be formed between the channel portion 36and the protruding member 41. To help improve the seal between these twocomponents, the protruding member 41 can be modified by providing stressrisers (45 and 46) on the inside 40 and the outside 41 of the protrudingmember 41 as shown in FIG. 14. The internal stress riser 46 provides asmooth surface at the interface with the valve ring sealing member 39.As noted above, the valve ring sealing member 39 can provide a seal asthe valve translates along the stem. Moving from the bottom to the topof the protruding member 41, the riser(s) 45 begin on the outside andthen move to the inside 46, allowing the splitting mechanism (crack) toprogress while maintaining a smooth outer surface between the valve ringsealing member 39 and the protruding member 41.

The stress riser 45 begins on the bottom of the sheath hub 47 andcontinues along the outside of the sheath hub until the stress riser 45reaches a point below the initial location of the valve ring sealingmember 39. At that point, the stress riser 46 moves to the inside of theprotruding member 41 and then continues to the notch 50. The depth andwidth of the stress risers 45 and 46 are selected depending on therequired separation force.

Another function of the stress risers 45 and 46 are to act as aninitiator in the splitting process. By their nature, the stress risersare the beginning of a split in the hub sheath 47 and, therefore, can beused to make the splitting process easier. Accordingly, the stressrisers 45 and 46 are located substantially on the axis where theintroducer 10 will be split.

Another optional modification that can be made to the sheath introducercomprises notches 50 in the upper portion of the protruding member 41that remain above the valve 30 in the extended position. The notches 50give the protruding member 41 additional length to extend past the valve30 while at the same time not adding additional length to the stressrisers 45 and 46. Such a configuration adds length to the protrudingmember 41 without increasing the cracking force needed to split theintroducer 10.

As shown in FIG. 14, the notches 50 are generally made to correspondwith the same location as the stress risers 45 and 46, i.e.,substantially along the axis of the expected split. The notches 50 canhave any shape that results in a concentration of the stress force.Examples of such shapes include substantial “V” shape or the substantialrectangular shape shown in FIG. 14.

The sheath hub 47 can also be optionally modified to increase theattachment between the sheath hub 47 and the sheath 53. One manner toincrease this attachment is depicted in FIGS. 15 and 16. In FIG. 15, thesheath has been modified to contain a sheath cap 57 with an interlockingfit between the sheath 53 and the sheath cap 57. The sheath cap 57contains grooves 58 which provide a location for the split ends 55 ofthe sheath 53 when the sheath is inserted though the sheath cap 57. Theends of the split sheath fold around the sheath retention cap 57 withtheir location maintained in the grooves 58. Once the sheath retentioncap 57 is assembled into the mating geometry of the sheath hub 47 asshown in FIG. 16, it locks the ends 55 of the split sheath tightly intothe hub 47. The sheath cap 57 is then affixed to the sheath hub 47.

In some embodiments, the sheath cap 57 can affixed to the sheath hub 47by means of a thermal, solvent or UV bond. In other embodiments, thesheath cap 57 can be affixed to the sheath hub 47 using a mechanicalconnection as known in the art, including a friction fit, snap fit, orultrasonic weld. One example of such a mechanical connection isillustrated in FIG. 20, where the sheath hub 47 had been provided with aconnector 72 containing male connections 71. The sheath cap 57 has alsobeen provided with a corresponding shape and size that will mate withthe connector 72, including female connections 73. When the sheath cap57 is moved towards the sheath hub 47, the male connection 71 slidesinto the female connection 73 and attaches the hub 47 and the cap 57 toeach other. Because of its shape, the cap 57 will also mate with theconnector 72 and can be configured, as shown in FIG. 20, to retain theends 74 of the sheath 53 between them.

Another method to increase the attachment sheath hub 47 and the sheath53 is illustrated in FIG. 21. As shown in FIG. 21, the sheath cap 57 hasbeen modified to contain extensions 75 that run substantially parallelto the body of the sheath hub 47. The extensions 75 have been configuredto substantially match the body of sheath hub 47. Likewise, the body ofsheath hub 47 has been configured to match the extensions of sheath cap57. Although many matching configurations can be used, the extensions 75contain ridges 77 that will substantially match notches 79 in the sheathhub. When the sheath cap 57 is moved towards the sheath hub 47, theridges 77 slides into the notches 79 and attaches the hub 47 and the cap57 to each other.

A similar, but different, configuration is depicted in FIGS. 22-23. Inthese Figures, the sheath hub bottom 107 has been modified to containextensions 175 that run substantially parallel to the body of the sheathhub top 118. The extensions 175 have been configured to substantiallymatch the body of sheath hub top 118. Likewise, the body of sheath hubtop 108 has been configured to match the extensions of sheath hub bottom107. Although many matching configurations can be used, the extensions175 contain ridges 177 that will substantially match notches 179 in thesheath hub top 118 and then wrap over the ends 180 of the sheath hubbottom 107. When the sheath hub bottom 107 is moved towards the sheathhub top 118, the ridges 177 slides into the notches 179 and attaches thehub top 118 and the sheath hub bottom 107 to each other, with thewrapping portions of the sheath hub bottom 107 aiding the attachment.

Alternatively, another method to increase this attachment is depicted inFIG. 17. In FIG. 17, the sheath hub 47 has been modified to encapsulatean end portion of the sheath 53. This encapsulation is performed so thatridges 59 overly the end 56 of the sheath 53, thereby retaining the endof the sheath underneath the ridges.

In yet another modification, the sheath introducer can be provided withmeans for separating the valve housing 33 away from the sheath hub 47.Any known means for forcing these two components apart can be used inthe invention, including leaf spring, coil spring, hinge, and/or amechanical lever. As depicted in FIG. 18, the forcing means comprises aspring 65. In its compressed state, the valve housing 33 and the sheathhub 47 are attached to each other by any mechanism, such as the snapfeatures 13 and 21 mentioned above and/or the lever 66. When the valvehousing 33 and the sheath hub 47 are attached, the valve 30 remainsclosed. The moment the user separates the sheath hub 47 from the valvehousing 33 by pressing on the grip section 52 (and/or disengaging thelever 66), the spring 65 is released from its compressed state and thesetwo components separate from each other.

One result of the separation of these two components is the movement ofvalve 30 relative to the protruding member 41. When these two componentsare attached to each other, the spring is compressed and the valve 30slides down the protruding member which then opens the slit 40 of thevalve 30. When these components are separated, the pressure of thespring 65 is released and it returns to the uncompressed state, slidingthe valve 30 back up the protruding member and closing the slit 40.

In another modification, the valve housing of the introducer could beengaged by means of a rotary movement along the axis of a threadedmember or any other mechanical means to translate the valve housingalong the desired path. For example, a mechanical lever, push button, orthreaded member could be used in this modification.

In addition to any previously indicated variation, numerous othermodifications and alternative arrangements may be devised by thoseskilled in the art without departing from the spirit and scope of theinvention and appended claims are intended to cover such modificationsand arrangements. Thus, while the invention has been described abovewith particularity and detail in connection with what is presentlydeemed to be the most practical and preferred aspects of the invention,it will be apparent to those of ordinary skill in the art that numerousmodifications, including but not limited to, form, function, manner ofoperations and use may be made without departing form the principles andconcepts set forth herein.

1. A splittable sheath introducer, comprising: a sheath; a hub disposedat a proximal end of the sheath; a valve included with the hub; and avalve actuator movable from a first position to a second position, thevalve actuator opening the valve when in the second position, whereinthe valve actuator further includes a retaining member that enables thevalve actuator to be retained by a portion of the hub when the sheathintroducer is split apart.
 2. The sheath introducer as defined in claim1, wherein the valve actuator engages a corresponding retaining memberof the hub such that the valve actuator is retained by a portion of thehub when the sheath introducer is split apart.
 3. The sheath introduceras defined in claim 2, wherein the retaining member of the valveactuator includes a tongue longitudinally defined on an outer surface ofthe valve actuator, and wherein the retaining member of the hub includesa groove that receives the tongue of the valve actuator.
 4. The sheathintroducer as defined in claim 1, wherein the valve actuator issubstantially coaxial with a longitudinal axis of the sheath introducer,and wherein the valve actuator further includes a conduit that enablespassage of a catheter through the valve actuator and through the valvewhen the valve actuator is in the second position.
 5. The sheathintroducer as defined in claim 4, wherein the valve actuator isnon-splittable and further includes a longitudinally defined channel forenabling the removal of the catheter therefrom when the sheathintroducer is split.
 6. The sheath introducer as defined in claim 1,wherein the hub is formed from a translucent material to enable a userto view the cavity of the hub.
 7. The sheath introducer as defined inclaim 6, wherein the hub further includes a magnifier portion thatmagnifies a portion of the cavity of the hub.
 8. The sheath introduceras defined in claim 1, wherein the valve actuator includes a top surfacethat enables the valve actuator to be pressed by a user from the firstposition to the second position.
 9. The sheath introducer as defined inclaim 1, wherein a bottom portion of the valve actuator includes anextended surface that opens the valve when the valve actuator is in thesecond position.
 10. The sheath introducer as defined in claim 12,wherein the extended surface of the valve actuator defines a crosssectional shape selected from the following: a C-shape; and a U-shape.11. A splittable sheath introducer, comprising: a sheath; a hub disposedat a proximal end of the sheath; a valve disposed in the hub; and avalve actuator including: a body defining a conduit extending from aproximal end to a distal end thereof, the body further defining alongitudinal channel in communication with the conduit; and a surface onthe body for enabling a user to apply force to the valve actuator in adirection substantially coaxial with a longitudinal axis of the valveactuator, the force enabling movement of the valve actuator from a firstposition to a second position, wherein the distal end of the valveactuator opens the valve when the valve actuator is moved from the firstposition to the second position.
 12. The sheath introducer as defined inclaim 11, further comprising: at least one interference feature definedby the actuator body, the interference feature enabling one-way movementof the actuator from the first position to the second position; and atleast one interference feature defined by the hub that engages the atleast one interference feature of the valve actuator to prevent movementof the valve actuator from the second position to the first position.13. The sheath introducer as defined in claim 12, wherein: the at leastone interference feature of the valve actuator includes a plurality ofteeth circumferentially defined about a portion of the outer surface ofthe actuator; and the at least one interference feature of the hubincludes a plurality of teeth defined on an inside surface of the cavityof the hub.
 14. The sheath introducer as defined in claim 11, whereinthe valve actuator is disposed in a cavity of the hub, and wherein thesheath introducer further comprises: means for preventing separation ofthe valve actuator from a portion of the hub when the hub is split. 15.The sheath introducer as defined in claim 14, wherein the means forpreventing separation includes: a tongue defined on an outer surface ofthe valve actuator; and a groove defined on an inside surface of thecavity of the hub, the groove receiving the tongue of the valveactuator.
 16. The sheath introducer as defined in claim 15, wherein thegroove is interposed between a first plurality of teeth and a secondplurality of teeth defined on the inside surface of the cavity of thehub.
 17. The sheath introducer as defined in claim 11, wherein theconduit of valve actuator provides access to the sheath via the valvewhen the valve actuator is in the second position.
 18. A method forinserting a catheter, comprising: providing a splittable sheathintroducer, the sheath introducer including a sheath, a sheath hubdisposed at a proximal end of the sheath, a valve disposed in the sheathhub, and a valve actuator disposed in a cavity of the sheath hub;inserting a distal portion of the sheath into a portion of a body of apatient; moving the valve actuator from a first position to a secondposition so as to open the valve; inserting a catheter into the body ofthe patient through the open valve and the sheath via a conduit definedby the valve actuator; and splitting the sheath introducer such that thecatheter passes through a channel defined in the valve actuator and suchthat the valve actuator remains attached to a portion of the sheath hubafter the sheath introducer is split.
 19. The method for inserting asdefined in claim 18, wherein moving the valve actuator further comprisesmoving the valve actuator from the first position to the secondposition, wherein interference features included on at least one of thevalve actuator and the cavity of the hub prevent backward movement ofthe valve actuator from the second position to the first position. 20.The method for inserting as defined in claim 18, wherein moving thevalve actuator further comprises: moving the valve actuator from a firstposition to a second position via direct finger pressure on the valveactuator in a direction that is axially aligned with the valve actuator.